The Online Encyclopedia and Dictionary






Muscle relaxant

In medicine, a muscle relaxant is a drug that causes skeletal muscle contraction to cease. Muscle relaxants are used to facilitate surgery, to enable tracheal intubation and to facilitate mechanical ventilation.

Muscles relaxants typically work by blocking the effect of acetylcholine (ACh) at the neuromuscular junction.


Receptor blockers

Substances that compete with ACh, for the receptors on a muscle cell can be either depolarising, or non-depolarising.

Depolarising muscle relaxants activate the muscle briefly, before blocking it.

Non-depolarising relaxants block the ACh receptors without activating them.

Other mechanisms

Botulinum toxin, marketed as Botox for facial wrinkle removal, works by stopping the release of ACh from the presynaptic neuron.

Central acting muscle relaxants

Acting on smooth muscle

See also

Last updated: 05-07-2005 14:10:01
Last updated: 05-13-2005 07:56:04